Air conditioning installation with centrifugal sprayers

ABSTRACT

The invention concerns an air conditioning installation with centrifugal sprayers (1). Said installation is essentially comprised of centrifugal sprayers (1) each provided with a deflector (2) and connected to a loop circuit (3) incorporating a buffer reservoir (4) which is supplied with liquid, a centrifugal purifier (5), a filter (6), a pump (7), individual flow regulating devices (8) and a collective flow regulating electro-valve (9), controlled by a regulation device (10) which is servo-controlled by a temperature sensor (11) and by a hygrometry sensor (12). The driving motors (13) for the sprayers (1) are power supplied through an adjustable frequency inverter (14).

The invention concerns an air conditioning/treatment installation withcentrifugal sprayers.

On certain premises, the hygrometry and temperature have to be keptwithin values compatible with specific utilization of the premises,whatever the outside environmental conditions, as it is the case inbuildings equipped with a collective air conditioning installation,certain stores or warehouses, greenhouses and breeding/rearingbuildings.

Particularly in greenhouses, rather strictly controlled relativehumidity and temperature conditions have to be maintained which,combined with periodic, well-adapted waterings and treatments, enableobtaining maximum production output. In this area, it may be profitable(in order to restrict investment costs) to also use the hygrometriccontrol installation to ensure periodic phytosanitary treatment of theplants, or even to ensure watering.

Certain means are already available to ensure constant hygrometry ingreenhouses:

A device consisting of a rotary disk, notched on its periphery and whichreceives in its center the liquid then sprayed in the form of a thinnerand thinner film towards the disk periphery. The peripheral notchescreate cyclic cut-outs of the fluid film. The particle dimensiondecreases as a function of the rotary speed of the disk.

A device which combines air and water: water is sprayed by compressedair in a spray nozzle.

Pressurized water installations, which ensure very thin spraying bymeans of jet pipes of a very small section.

Ultrasonic division, by very fast compressed air passage through aspecial chamber, supplied with a fluid: this causes the fluid scatteringinto fine particles.

All the above devices are rather fragile, use a lot of power, are rathersusceptible to scaling and clogging and in certain cases, do not allowfor the required spraying fineness.

The present invention is designed to remedy such problems. The inventionas defined in the patent claims enables meeting the requirement todevelop an air conditioning installation capable of maintaining humidityand temperature within a well-defined range, and allowing for thedistribution of phytosanitary, nutritional, antiseptic or otherproducts.

This air conditioning installation (with centrifugal sprayers) is mainlycharacterized by its components: it consists of centrifugal sprayers,each provided with a deflector the shape and slant of which are afunction of the area to be covered. The sprayers are hydraulicallyconnected to a loop circuit incorporating a buffer reservoir (suppliedwith liquid), a centrifugal purifier, a self-cleaning filter, a pump,individual flow regulating devices, a collective flow regulatingelectro-valve controlled by a regulation device (which isservo-controlled by a temperature sensor and a hygrometry sensor). Thedriving motors for the sprayers are power supplied through an adjustablefrequency inverter.

The deflectors (fitted to the sprayers) present themselves in the formof a flat corolla (which may be concave or convex-shaped), secured tothe base of the driving motor and making an angle a (75° to 90°) withrespect to the motor shaft axis. The external edge of the deflectors iscircular, elliptical or rectangular shape. The internal edge of thedeflectors provides an opening around the base of the driving motors,with a passage section of approximately 1.5 times that of thecentrifugal spraying head.

The larger deflector dimension is approximately three times the outerdiameter of the centrifugal spraying heads, while the opening diameterroughly matches 1.5 times the outer diameter of the heads.

The internal edge of the deflectors is equipped with an annular gutter,for drippings recovery and recycling through a duct (which is connectedto the centrifugal sprayer hydraulic supply line).

The centrifugal spraying head is topped by a fixed disk, at anadjustable distance from the upper edge of the centrifugal sprayinghead. The distance X of the fixed disk with respect to the deflectoropening roughly matches one quarter of the spraying head diameter.

The invention advantages mainly reside in design simplicity, sincecentrifugal force ensures the scattering of liquids (even when loaded)and the deflector fitted to each sprayer ensures the spraying function.The spraying fineness adjustment function (through spraying headrotational speed adjustment) enables adapting the installation to anyrequired application.

Various features and advantages are mentioned hereinafter, in thedescription of the greenhouse air conditioning installation implementedaccording to this invention and given as a non restrictive example,cross-referenced to the appended drawings on which:

FIG. 1 is a front view of a centrifugal spraying device shown insection.

FIG. 2 is a functional diagram of the air conditioning installation.

FIG. 2 shows a greenhouse air conditioning installation mainly comprisedof centrifugal sprayers (1) each provided with a deflector (2) andconnected to a loop circuit (3) incorporating a buffer reservoir (4)which is supplied with liquid, a centrifugal purifier (5), aself-cleaning filter (6), a pump (7), individual flow regulating devices(8) and a collective flow regulating electro-valve (9) controlled by aregulation device (10) which is servo-controlled by a temperature sensor(11) and by a hygrometry sensor (12). The driving motors (13) for thesprayers (1) are power supplied through an adjustable frequency inverter(14).

FIG. 1 shows a centrifugal sprayer (1), fitted with a deflector (2),secured to the base of the driving motor (13), featuring an annulargutter (15), and that is connected to the supply piping (17) by means ofa duct (16). The centrifugal sprayer head (1) is topped by a disk (18)through which the supply piping (17) is routed: the disk is attached (bymeans of an adjustable device) to the piping, so as to enable changingthe separation distance Y of the centrifugal sprayer head (1). Theadjustment is made by means of a locking screw (19).

As shown in FIG. 2, the internal edge (2b) of the deflector (2), aroundthe base of the driving motor (13), allows for an air passage around themotor: the air circulation, combined with the shape and slant angle a ofthe deflector (2), results in long range projection of the liquidparticles by Coanda effect (the throwing effect may be augmented byusing a concave or convex-section corolla). The area covered by eachsprayer is adjustable as a function of the shape of the deflectorexternal edge (2a). Specifically, a rectangular shape enables coveringthe greenhouse over the maximum possible portion of its length, whilerestricting the crosswise covering to the useful width of thegreenhouse, in order to avoid throwing projections to the walls.

The drippings collected on top of an underneath the deflector (2) arerecovered in the annular gutter (15) (slit outwards) and then directlyrecycled into the spraying head (1) through the duct (16) and piping(17).

The separation distance of the deflector (2) with respect to thespraying head (1), as well as its slant angle a with respect to theperpendicular plane to the shaft axis of the motor (13), determine theprojection angle. The optimum angle a is approximately 15°. A givenseparation distance Y of the fixed disk (18) with respect to the upperedge (1a) of the spraying head (1), allows for air penetration into thespraying head cavity; this improves liquid spraying and flowing. The airproportion with respect to the liquid flow rate is adjustable by meansof the locking screw (19).

On FIG. 2, one will note that the rotational speed of the centrifugalsprayers (1) (and, consequently, the spraying degree) can becollectively adjusted by acting on the frequency inverter (14). Flowrates may be individually adjusted by acting on the adjustment devices(7). Maintaining a given hygrometry and temperature within the enclosureis ensured through sensors (11) and (12) of the regulation device (10)which controls the collective flow regulating electro-valve (9) (for thesprayers (1)), from the supply loop (3) feedback line.

The buffer reservoir (4) supply is regulated by means of a float.

The driving motors of the centrifugal sprayers (1), of a 180-200 Wattpower, ensure head motion driving at 3,500 RPM, under 50 Hz frequency;the frequency inverter (14) raises this frequency to 10,000 RPM for 150Hz, then to 15,000 RPM for 200 Hz (which corresponds to fogging speed).

In the case of a 20-25 KW power installation, it is possible to operate50 to 60 spraying heads simultaneously, which enables spraying 10,800liters per hectare per hour.

We claim:
 1. An air conditioning installation with centrifugal sprayers,characterized by it mainly comprising of centrifugal sprayers (1) eachprovided with a deflector (2) the shape and slant angle of which aredefined as a function of the area to be covered; wherein the sprayersare hydraulically connected to a loop circuit (3) including: a bufferreservoir (4) which is supplied with liquid, a centrifugal purifier (5),a self-cleaning filter (6), a pump (7), individual flow regulatingdevices (8) and a collective flow regulating electro-valve (9)controlled by a regulation device (10) which is servo-controlled by atemperature sensor (11) and by a hygrometry sensor (12); wherein thedriving motors (13) for the centrifugal sprayers (1) are power suppliedthrough an adjustable frequency inverter (14).
 2. An air conditioninginstallation according to claim 1, wherein the deflectors (2) with whichare fitted the centrifugal sprayers (1) consist of a flat corolla,concave or convex-shaped, secured to the base of the driving motor (13)and forming an angle a (75° to 95°) with respect to the driving motorshaft axis.
 3. An air conditioning installation according to claim 1,wherein the external edge (2a) of the deflectors (2) is of circular,elliptical or rectangular shape.
 4. An air conditioning installationaccording to claim 1, wherein the internal edge (2b) of the deflectors(2) allows for a remaining passage, around the base of the motor (13)and of a cross section approximately matching 1.5 time that of thecentrifugal sprayer head (1).
 5. An air conditioning installationaccording to claim 1, wherein the opening diameter of the deflectors (2)approximately matches 1.5 times the external diameter of the centrifugalsprayer head (1).
 6. An air conditioning installation according to claim1, wherein the deflectors (2) match, in their larger dimension,approximately three times the external diameter of the centrifugalsprayer heads (1).
 7. An air conditioning installation according toclaim 1, wherein the internal edge (2b) of the deflectors (2) isprovided with an annular gutter (15) which ensures recovery of thedrippings and their direct recycling through a duct (16) connected tothe supply piping (17) of the centrifugal sprayer head (1).
 8. An airconditioning installation according to claim 1, wherein the sprayer head(1) is topped by a fixed disk (18), of which the distance with respectto the upper edge (1a) of the centrifugal sprayer head (1) isadjustable.
 9. An air conditioning installation according to claim 8,wherein the disk (18) is secured to the supply piping (17), whichcrosses through the disk, the attachment function being ensured by alocking screw (19).
 10. An air conditioning installation according toclaim 8, wherein the fixed disk (18), which is mounted on top of thesprayer head (1), is located at a distance X with respect to the openingof the deflector (2), the distance X approximately matching one quarterof the centrifugal sprayer head (1) diameter.